Purpose: To determine the clinical characteristics, possible etiologic agents, and response to oral antibiotic therapy in patients with phlyctenular keratoconjunctivitis. Methods: The authors reviewed the medical records of the 17 patients with phlyctenular keratoconjunctivitis who were seen and treated at the Bascom Palmer Eye Institute between 1981 and 1991. Results: All 17 patients were younger than 18 years of age at the onset of their disease. Girls (n =14) outnumbered boys (n = 3) 4:1. Significant incapacitating symptoms and ocular morbidity occurred frequently, including three perforated corneas. Five of ten patients who were tested for Chlamydia infection had positive test results and five patients possibly had early rosacea dermatitis. All patients experienced long-term remission of their ocular disease after a course of oral tetracycline or erythromycin. Two patients demonstrated unique linear (fascicular) corneal phlyctenules. Conclusion: Oral tetracycline or erythromycin treatment produces long-lasting remission of phlyctenular keratoconjunctivitis in affected children.